The Health Benefits of Oats (Avena Sativa)

For Lowering Cholesterol, Preventing Heart Disease, and More

Oats (Avena sativa L.) are grown worldwide and provide a necessary food staple for people in many countries. Avena sativa is commonly eaten or taken as a medicinal supplement for its highly-acclaimed health benefits.

The plant is comprised of a seed (oat), leaves and stems (oat straw), and bran (the outer layer of the whole oats). Various parts of the Avena sativa plant are used to make medicinal herbal supplements, providing a wide range of health benefits.

This article discusses the parts of the Avena sativa plant, the health benefits, and possible side effects. It also covers the different oat products and how they're prepared.

Other common names for Avena sativa include:

  • Oats
  • Avena (Spanish)
  • Hafer (German)
  • Ma-karasu-mugi (Japanese)

Parts of the Plant

The various parts of the plant include:

  • The fresh milky seed: These are oats that are harvested early, during the “milky” stage. Early-harvested oats have the highest level of minerals, such as potassium and magnesium, and are available as a supplement.
  • The mature seed: These are eaten as food (oatmeal). Oatmeal is rich in nutrients such as silicon, manganese, zinc, calcium, phosphorus, and vitamins A, B1, B2, and E. This is the endosperm, which is the usual product of milling.
  • Whole oat groats: Groats are whole grains. The hulled kernels include the cereal germ, fiber-rich bran, and endosperm. Whole oat groats contain high levels of nutrients such as soluble fiber, proteins, unsaturated fatty acids, vitamins, minerals, and other phytochemicals.
  • Oat straw: These are the leaves and stems of the plant, which contain very high iron levels, as well as manganese and zinc.
  • Oat beta-glucan (oat bran): This soluble fiber has been linked to improving heart health and lowering cholesterol. Oat bran can be found as a whole-grain food product as well as a medicinal supplement.

The outer husk of the oat must be removed, as it is not digestible by humans.

Health Benefits

Oats are a rich source of protein, minerals, fats, beta-glucan, polysaccharides (complex carbohydrates), and dietary fiber. They also contain many other nutrients such as antioxidants, and lipid (fat) lowering chemicals, which include flavonoids, saponins, and sterols.

Avena sativa has been examined in clinical research studies as a remedy for many medical conditions. However, more clinical research evidence is needed to prove its safety and effectiveness.

Oats have been linked to benefits in conditions such as:

  • Anxiety
  • Bladder weakness
  • Constipation
  • Diverticulosis
  • Gout
  • Inflammatory bowel disease
  • Irritable bowel syndrome (IBS)
  • Joint and tendon disorders
  • Kidney conditions
  • Nerve disorders
  • Opium and nicotine withdrawal
  • Gallstones
  • Skin disorders
  • Stress

Oats have been examined in clinical research studies and found to offer many health-promoting effects. Oat bran may block substances that contribute to diabetes and high cholesterol. It may also provide a feeling of fullness, helping to promote weight loss.

Antioxidant Effects

A 2015 research paper reported that oats contain several antioxidants, which help prevent cell damage.

These include:

Cholesterol-Lowering Effects

Studies have found that oat beta-glucan may lower fats (lipids and lipoproteins) in the blood. Eating oatmeal and oat bran lowers total blood cholesterol and "bad" cholesterol, or LDL (low-density lipoprotein) cholesterol levels.

In a 2016 study, oat bran as a fiber source significantly lowered lipoproteins, both total cholesterol, and LDL. Lipoproteins are a combination of proteins and fats that move through the blood. By reducing these lipoproteins, oat bran lowered the risk of heart disease in those with mildly high cholesterol levels.

Avena sativa is thought to lower cholesterol by providing high amounts of fiber in the diet. At least 750mg of soluble fiber per serving supports health claims of lowering the risk of heart disease.

Heart Health

In 1997 the Food and Drug Administration (FDA) approved the heart health benefit of fiber from oats. It started allowing products to list this benefit on their packaging. Oat bran was also found in some studies to lower blood pressure.

Weight Reduction

In a clinical trial, study participants with similar weight classes were divided into two groups. One group was treated with beta-glucan oat cereal; the other took a placebo.

After 12 weeks, those who ate oats reduced body weight, body fat, and waist-to-hip ratio measurement. There were no adverse effects in any of the study subjects.

Antidiabetic Effects

Research is still not conclusive about whether oats are beneficial for blood sugar control.

Whole-grain foods like oats have been associated with lower risk of chronic disease, such as type 2 diabetes. Studies have been done to explore whether long-term intake of oats or oat bran improves insulin sensitivity. However, a 2014 review of studies found no evidence that oats are effective in that capacity.

Another review of studies found oat bran beta glucan (oat bran) had a beneficial effect on metabolic syndrome, a group of conditions that can lead to diabetes or heart disease. It also had a positive effect on glycemia or glucose in the blood.

Antimicrobial Effects

Extracts from Avena sativa were found to offer antibacterial properties against Staphylococcus aureus, and E. coli, as well as other bacteria.

Skin Benefits

Studies found that oatmeal preparations (such as an oatmeal bath, emollients, and oat colloidal extracts) were effective in treating inflammatory skin conditions.

These include:

  • Dermatitis (inflammation of the skin)
  • Pruritis (a condition of the skin involving itching)
  • Acne
  • Eczema (treated with dried seed decoction)

Nervous System Effects

Studies found that Avena sativa supported cognitive performance in stressful situations and boosted overall healthy mental functioning.

In one study, a 1,600mg dose of oat herb extract was found to improve attention, concentration, and the ability to maintain focus during tasks performed by adults at various levels of cognitive functioning.


Older studies of Avena sativa reported that extracts lowered the craving for nicotine, reducing the number of cigarettes smoked each day. 

Gastrointestinal (GI) System

Oat bran has been studied as a possible treatment for GI disorders, such as ulcerative colitis. One older study showed oat bran may help increase gut flora and provide relief of abdominal pain.

Immune Response

Studies have found that beta glucan helped white blood cells reach the site of infection quickly and improved the white blood cell’s bacteria-killing properties.

Possible Side Effects

Oat products are considered likely safe for most people, including:

  • People who are pregnant
  • People who are breastfeeding or chestfeeding
  • Children


A contraindication is a specific situation where a treatment, drug, or supplement, should not be given because it may cause harm. 

Contraindications for taking oat products include:

People who have IBS should avoid bran.

Side Effects

Side effects of oats may include:

  • Flatulence (gas)
  • Bloating
  • Anal irritation
  • Skin irritation when oat containing products are used topically (on the skin)

To minimize side effects, start with smaller servings and gradually increase.

Special Precautions

You should be careful with eating oats if you have trouble chewing or swallowing, such as after a stroke or if you have loose teeth or ill-fitting dentures. When oats are not chewed properly, a blockage in the intestines could occur.

Oats, oat milk, oat bran

Verywell / Anastasia Tretiak

Selection, Preparation, and Storage

Oat bran products should be taken along with plenty of water to ensure good distribution of the fiber in the digestive system.

The Dietary Reference Intake for total fiber for adults age 50 or younger is 38 grams for people assigned male at birth and 25 grams for people assigned female at birth. For those over age 50, it is 30 grams per day for people assigned male at birth and 21 grams for people assigned female at birth. A 1/2 cup of Quaker oats (dry) contains 4 grams of fiber.

Milky oats are harvested during a stage that only lasts around a week. This occurs before the oat begins to flower and before the seed hardens into the oat grain commonly eaten at breakfast. A tincture of milky oats is made to preserve the potency of the plant. A dried form is also made and used as a nutritive tonic.


When purchasing supplements from the Avena sativa plant, look for organic, all-natural, and certified to ensure purity and potency. The certification should be from a third-party organization, such as the U.S. Pharmacopeia, NSF International, or

If it's possible, check to see that an oat product, such as milky oats, has been harvested at the right time in the plant’s growth stage. This is important for getting a product that has therapeutic, health-boosting properties.

Types of Oats as Food Sources

There are several types of oats available as food sources. The nutritional content is relatively the same whether the oats are cut, rolled, or ground. 

They differ in their fiber content, as well as the time it takes to prepare them.

Whole-Grain Oats

Whole grain oats are also known as whole oat groats or whole oat kernels. This type of oat food product is minimally processed. The outer (inedible) hull is removed but they still have a chewy texture and are said to taste best when eaten hot. Whole grain oats may take up to an hour to cook.

Steel-Cut Oats

Steel-cut oats are whole oat groats, but they have been cut into smaller pieces to decrease the cooking time. Instead of taking an hour to cook, steel-cut oats take only about 20 minutes.

Scottish Oats

Oats that are ground into broken pieces take only about 10 minutes to cook on high heat. Scottish oats originated in Scotland, have a creamy texture, and are perhaps the best choice for making refrigerated oats.

Rolled Oats

Rolled oats, such as the Quaker brand, are steamed and softened, then they are rolled into flakes. The processing lengthens the shelf life of the product without substantially impacting the nutritional value. They are quick to cook, taking approximately 10 minutes.

Instant Oats

Instant oats are steamed and rolled, but for a longer time than rolled oats. They are partly cooked when purchased. They have a creamy, non-chewy texture, and can be prepared quickly by adding hot water. The health benefit is close to that of rolled oats. Try to avoid the sugar-laden pre-sweetened/flavored variety of instant oats.

Oat Bran

Oat bran is very high in soluble fiber. It’s not considered a whole grain because it is comprised of just the bran layer, but it offers the health benefits of whole grain. Oat bran can be cooked in just a few minutes on the stovetop. It can also be added to other cereals, yogurt, or smoothies to increase the daily fiber content in the diet.


Several studies involved the use of Avena sativa, which was ingested as a tea made with 3 grams of the plant, boiled in 250 milliliters (ml) of water. After straining and cooling the tea, it was taken several times each day and shortly before going to bed at night.


Oats from the Avena sativa plant have been shown in studies to have health benefits. These include lowering cholesterol, helping reduce weight, and improving heart health. Some people should avoid oats, such as those with celiac disease or intestinal obstructions.

Various types of oats are available for different tastes. The main differences in products are the amount of fiber and the cooking time needed.

Frequently Asked Questions

  • Can oats be eaten raw?

    Yes, Soaking raw oats overnight in any type of milk (for example, cow's milk or a nut milk such as almond, cashew, or coconut) in the refrigerator will soften them enough to be eaten. One cup of milk to one cup of oats is a good ratio. Overnight oats can be flavored and enhanced with fresh or dried fruit, raw or roasted nuts or seeds, nut butter, fresh coconut, granola, spices, orange zest, or vanilla extract.

  • What nutrients are in oat milk?

    One cup (8 ounces) of unsweetened oat milk contains:

    • 120 calories
    • 3g protein
    • 16g carbohydrates
    • 5g fat
    • 1.9g fiber

    Most brands are fortified with calcium, vitamins A and D, and riboflavin. Oat milk tends to have a bit more fiber than other plant-based milks.

  • When can babies begin eating oats?

    Babies usually can start eating oatmeal as soon as the pediatrician gives the OK to start solid foods—typically around 6 months but no earlier than 4 months.

15 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Sherry Christiansen
Sherry Christiansen is a medical writer with a healthcare background. She has worked in the hospital setting and collaborated on Alzheimer's research.